Did you by any chance have engineered modules? as there was a cheat to engineer grade 5 modules and only pay for grade 1. And all those players who did this cheat have been stripped of their modded modules, regardless of what ships they are on or if that particular module was cheated or not.
And to clarify on
metatheurgist advice, we have module transfer, so buy a cheap sidewinder, fly to a nearby place that sells FSD for ananconda and a ships that hold that, buy that donor ship, buy the wanted FSD, store the OLD fsd, now swap the FSD with the stored FSD, sell the donor ship, and get back into your sidewinder, and fly back, and transfer your stored FSD to your location. and in a hopyfully short time, the FSD will arrive and you can fly your anaconda to a new location.
We also have ship transfer, so once you reach a good starport that sells FSD and hopefully other good modules to your anaconda, transfer you anaconda there. It might cost more, to do it this way. But would most likely be more convienient.
And ofcourse, amcb10 advice to open a support ticket is also a good way to go, it could be that you savefile (stored on Frontiers servers) got damaged in one of the upgrades or something. It is computers we are talking about so some fluke solar flare could for unknown reasons just affect your savegame for some strange reason.